CITY OF HUNTSVILLE ENGINEERING DEPARTMENT

Transcription

1 CITY OF HUNTSVILLE ENGINEERING DEPARTMENT DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS March 2011

2 CITY OF HUNTSVILLE DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS LIST OF REVISIONS SECTION List of Figures Section 2.0 Section 3.0 Section 4.0 Section 5.0 Section 6.0 Section 7.0 Section 8.0 REVISION Deleted Figure 2.1 Ratio of Peak Hourly Flow to Design Average Flow. Renamed Figure 2.2 Computations for Sanitary Sewer Design to Figure 2.1. Renamed Figure 2.3 Sample Computations for Sanitary Sewer Design to Figure 2.2. Deleted Section 2.0 Sanitary Sewer Capacity Determination Table of Contents Replaced obtained from the curve shown in Figure 2.2 with obtained from the equation shown in Figure 2.2. Deleted Section 3.0 Design Criteria for Manholes Table of Contents 3.2 Replaced Kor-N-Seal with A-Lok. 3.6 Revised section to include shallow manholes, minimum and maximum height above 100-year flood elevation, and added watertight manholes and vents. 3.9 Replaced Kor-N-Seal with A-Lok Revised testing requirements Added lateral connections. Deleted Section 4.0 Design Criteria for Sewer Lines Table of Contents. Table 4.2 Revised minimum allowable slopes Added section Added section. Deleted Section 5.0 Design Criteria for Service Laterals Table of Contents. 5.1 Added Service lateral locations shall be shown on all as-built drawings 5.1 Added Service lateral connections are not allowed on gravity sewer lines with diameters larger than Added Service lateral connection shall be made with wye, teewye, or other approved fittings only Added Clarification Statement. 5.6 Revised curb markers. 5.7 Added Oil, Water, and Grease Separation section. 5.8 Added Lateral Connections to Manholes section. Deleted Section 6.0 Plan Set Requirement Table of Contents. Deleted Section 7.0 Construction Administration Table of Contents. Added the following details: SD-8A, SD-8B, SD-22A, SD-22B, SD- 22C, SD-23, SD-24, and SD-25. Replaced SD-13 with Manhole Venting Detail. List of Revisions

3 CITY OF HUNTSVILLE DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS TABLE OF CONTENTS SECTIONS SECTION 1 SECTION 2 SECTION 3 SECTION 4 SECTION 5 SECTION 6 SECTION 7 SECTION 8 INTRODUCTION SANITARY SEWER CAPACITY DETERMINATION DESIGN CRITERIA FOR MANHOLES DESIGN CRITERIA FOR SANITARY SEWER LINES DESIGN CRITERIA FOR SERVICE LATERALS PLAN SET REQUIREMENTS CONSTRUCTION ADMINISTRATIONS CHECKLISTS APPENDICES APPENDIX A APPENDIX B APPENDIX C MISCELLANEOUS FLOW DATA AND CHARTS STANDARD DETAILS STANDARD SPECIFICATIONS Table of Contents

4 CITY OF HUNTSVILLE DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS LIST OF ABBREVIATIONS ADEM...Alabama Department of Environmental Management Avg....Average COH...City of Huntsville Conc....Concrete Dia....Diameter DIP...Ductile Iron Pipe Elev....Elevation Equiv....Equivalent Ex./Exist...Existing Fps...Feet per Second Ft...Feet Gpd...Gallons per Day I/I...Infiltration & Inflow In....Inches Max....Maximum MH...Manhole Min....Minimum OSHA...Occupational Safety & Health Association Psi...Pounds per Square Inch PVC...Polyvinyl Chloride RCP...Reinforced Concrete Pipe SRF...State Revolving Fund TCE...Temporary Construction Easement TVA...Tennessee Valley Authority Typ....Typical List of Abbreviations

5 CITY OF HUNTSVILLE DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS LIST OF FIGURES FIGURE LOCATION FIGURE COMPUTATIONS FOR SANITARY SEWER DESIGN SECTION 2 FIGURE SAMPLE COMPUTATIONS FOR SANITARY SEWER DESIGN SECTION 2 FIGURE SAMPLE PLAN SET SECTION 6 FIGURE SANITARY SEWER PLANS REVIEW CHECKLIST SECTION 8 List of Figures

6 CITY OF HUNTSVILLE DESIGN AND ACCEPTANCE MANUAL FOR SANITARY SEWERS LIST OF TABLES TABLE LOCATION TABLE COMMERCIAL/INDUSTRIAL WASTEWATER FLOWS SECTION 2 TABLE HYDRAULIC ELEMENTS CHART SECTION 2 SECTION 2 TABLE LINE LENGTH BETWEEN MANHOLES SECTION 3 TABLE PIPE MATERIAL SELECTION SECTION 4 TABLE MINIMUM ALLOWABLE SLOPES SECTION 4 TABLE MAXIMUM ALLOWABLE SLOPES SECTION 4 TABLE EASEMENT WIDTHS SECTION 4 TABLE A-1 - DESIGN BASIS FOR WASTEWATER FLOWS OF NEW SEWAGE WORKS APPENDIX A TABLE A-2 - DEVELOPED AREA WASTEWATER FLOWS APPENDIX A List of Tables

7 SECTION 1.0 INTRODUCTION This manual will address the following: 1. Basic methodology of the planning and design of a sanitary sewer. 2. Manhole and pipe materials accepted by the City of Huntsville. 3. Standard details for construction accepted by the City of Huntsville. 4. Standard practices accepted by the City of Huntsville. 5. Checklists for submittals to the City of Huntsville. 6. Requirements for Plans submitted to the City of Huntsville. 7. Updated Standard specifications accepted by the City of Huntsville. This manual is only intended as a guide to the design of public and private sanitary sewers and not as a step-by-step design manual. All circumstances encountered during planning and design cannot be contained in a manual. In these instances, engineering judgement and experience must be applied. For any questions or criteria not covered by this manual refer to the Recommended Standards for Wastewater Facilities, Great Lakes Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers, Ten States Standards, latest revision. (These manuals are available from the Health Education Services, PO Box 7126, Albany, NY 12224, Phone (518) , Web site at Plans approved by the City of Huntsville Engineering Department shall be constructed in a manner consistent with the letter and intent of this manual and shall not be construed as having any authority to violate, cancel, alter, or set aside any of the provisions of this manual, nor shall issuance of approval prevent the City of Huntsville Engineering Department from thereafter requiring a correction of errors in plans, errors in construction or violations of these regulations. In addition, the regulations included in this manual consist of a minimum standard and may be supplemented as determined appropriate by the City of Huntsville Engineering and Water Pollution Control Departments. The items of consideration for basic sanitary sewer design consists of several key elements. Some of the key elements to consider are listed below. 1. Location - Locating the best possible path or alignment for the proposed sewer that will allow effective sanitary sewer service to the most people. 2. Restrictions Existing sewer elevations, sewer depth required to service users, environmentally sensitive areas, wetlands, archaeological considerations, creek crossings, underground utilities or facilities, railroads, highways, property values and easements, floodplains, potential development, high usage or aesthetics, minimum cover, minimum slopes, and rock, sinkholes, or other topographic features. 3. Design Flow Acceptable pipe size to transport the existing and future design flows. 1-1

8 4. Pipe Material and Construction Methods Appropriate pipe type and bedding designed to meet the requirements for depth of bury, typical terrain, and other project specific criteria. 5. Manholes and other Appurtenances - All sanitary sewer facilities shall be designed in accordance with all rules, regulations, and standards of the City of Huntsville - Engineering Department, Alabama Department of Environmental Management, and all other governing agencies. Sanitary sewer plans and specifications shall be prepared in accordance with these design standards and a professional engineer registered in the State of Alabama shall stamp all construction documents. City Engineering shall also approve the plans. Three other City of Huntsville manuals exist that address sanitary sewers. These manuals are as follows: City of Huntsville, City Engineer, Standard Specifications For Construction of Public Improvements Contract Projects, 1991; City of Huntsville, City Engineer, Engineering Standards For Construction of Public Improvements, 1991; and City of Huntsville, 2003 Master Sewer Plan, December Material covered in this manual will take precedence over the above-mentioned City of Huntsville manuals. Refer to these manuals for additional specifications not directly related to sanitary sewers or their construction such as pavement replacement, seeding and mulching, etc. 1-2

9 SECTION 2.0 SANITARY SEWER CAPACITY DETERMINATION 2.1 Planning Period In order to determine the capacity for a sanitary sewer, population and land use projections for the sewer s service area shall be made for a 20-year planning period, and also the saturation condition based on information obtained from the City s Planning Division. 2.2 Service Area Land Use and Population Projections The land use and population projections for a sanitary sewer shall be coordinated with the City s latest wastewater system improvements master plan and with the City Planning Division to incorporate the latest revisions in the projections. 2.3 Wastewater Flow Projections Wastewater flows shall be estimated from population projections, commercial/ industrial land usage and an estimated infiltration/inflow (I/I) in the sanitary sewer service area, all for a 20-year planning period. The sewer shall be designed for an estimated peak hourly flow as described below Residential Flows: The residential wastewater flows shall be calculated using an average per capita per day flow of 100 gallons. This number includes a 25% allowance for potential inflow and infiltration (I/I). However, an additional allowance should be made where conditions are unfavorable, such as areas of known high groundwater. When historical wastewater flow records are not available, the ratio of peak hourly flow to estimated average daily domestic wastewater flow can be obtained from the equation shown in Figure Commercial /Industrial Flows: When no specific flow data is available, Table 2.1 shall be used for estimating peak commercial/industrial flows. Every effort shall be made to obtain accurate data as the flows vary widely depending upon specific needs of the user. A list of known industrial users may also be prepared for planning purposes. The industrial users flow may be estimated using water usage records. Included in Appendix A are two charts of standard wastewater flow data assumptions for different types of developments. These charts can be used for flow projections, if no other data is available. 2-1

10 2.3.3 Total Peak Flow: Total peak hourly design flow can be calculated by adding the residential and the commercial/industrial peak flows. Sample design flow calculations are as follows: 1. Average Daily Flow = 100 gallons/person/day x Total Equivalent Population TABLE Peak Design Flow = Average Daily Flow x Peaking Factor COMMERCIAL/INDUSTRIAL WASTEWATER FLOWS*** Commercial Flow (gpd/acre) Industrial Flow (gpd/acre) Avg. Daily I/I Total Avg. Daily Peak** Flow Avg. Daily Total Avg. Daily Peak** Flow ,000 1, ,625 3,250 * Additional allowance shall be made where conditions are unfavorable ** Based on a peaking factor of 2.0 *** Reference: City of Huntsville, 2003 Master Sewer Plan, Latest Edition 2.4 Collector Sewers Collector sewers transport wastewater directly from property service connections. Changes in land use can have a significant impact on the quantity of flow to a collector sewer. For this reason, collector systems shall be designed to transport the saturation flows of the service area, except as otherwise required by the latest edition of the City of Huntsville Master Sewer Plan. For further information on design flows and saturation flows, refer to the latest City of Huntsville, Master Sewer Plan. 2.5 Interceptor Sewers Interceptor sewers are principal sewers to which collector sewers are tributary. All interceptor sewers shall be designed to transport the saturation levels of the cumulative collector sewer drainage areas, except as otherwise required by the latest edition of the City of Huntsville Master Sewer Plan. For further 2-2

11 information on design flows and saturation flows, refer to the latest City of Huntsville, Master Plan. 2.6 Submittals An Engineering Report on flow calculations must be reviewed with City Engineering before final design is accepted. This review will afford City Engineering the opportunity to alter specific design criteria if needed. Required items for the Engineering Report on Flow Calculations are as follows: 1. Topographic map outlining the drainage area. Service area and acreage for each zoning classification shall be shown. 2. General layout of the proposed sanitary sewer line. 3. Flow Calculations population of each drainage basin; all present and future users. Must include all assumptions with basis for determining numbers. Use the included calculation form at the end of this section (Figure 2.2). Electronic copies of the calculation sheet are available from the City Engineering office or the website. 4. Appropriate Peaking Factor used for zoning or individual basins. 5. The minimum design velocity shall be 2.0 fps and the maximum design velocity shall be 10.0 fps. In areas where velocities exceeding 10.0 fps are needed due to the existing site conditions, such as mountainside development, prior approval from City Engineering is required. Appropriate design for safety and durability under the increased stress shall be incorporated into the plans and specifications for these higher velocity sections of pipe. 2-3

12 TABLE 2.2 HYDRAULIC ELEMENTS CHART q/qfull v/vfull d/dfull

13 FIGURE 2.1 COMPUTATIONS FOR SANITARY SEWER DESIGN Assumed Percentage of Saturation = % Date: Sheet: of Computed By: Checked By: ENGINEER Location Invert Elevs. Mahole Drain. Area Designation Sewer Line Designation From To Increment Population Cumulative Population Residential Peak Factor Increment Commercial Acres Increment Industrial Acres Increment Peak Inflow GPD Design Q Length Upper End Lower End MH# MH# cfs LF ft ft ft/ft Inch cfs fps Ratio d/d d/d Ratio fps Slope Size Pipe Material Manning's n "Q" Full "V" Full Design "Q" "Q" Full Flow Depth Ratio Maximum Flow Depth Ratio Design "V" "V" Full Design "V" Notes: Column 1 Drainage Area Designation Column 2 Sewer Line Designation (Will be Used for Final Design) Column 3 Manhole Designation Column 4 Projected (20-year) Population from Each Individual Drainage Area. Column 5 Total Population Obtained from All Drainage Areas Contributing to that Point. Column 6 Residential Peak Factor. Peak factor = (18+(P) 1/2 )/(4+(P) 1/2 ) Column 7 Amount of Commercial Area Contained Within the Drainage Area in Acres. Column 8 Amount of Industrial Area Contained Within the Drainage Area in Acres. Column 9 Peak Flow Contributed by the Individual Drainage Area. ((Pop x Res Peak Factor x 100 gpcd) + (Comm. area x 1000 gpd/ac) + (Ind. Area x 3250 gpd/ac)) x Percentage of Saturation Column 10 Design Flow Capacity = Total Accumulated Peak Sewage Flow at that Point in Cubic Feet per Second Column 11 Length of Pipe Measured from Center of Manhole to Center of Manhole Column 12 Upstream Manhole Invert Elevation. Column 13 Downstream Manhole Invert Elevation. Column 14 Design Slope = (Upstream Invert - Downstream Invert - Drops Across Intermediate Manholes) / Length Column 15 Pipe Size Column 16 Pipe Material Column 17 Manning's n value (0.011 for PVC and for DI) Column 18 "Q" Full calculated using Manning's equation Column 19 "V" Full calculated using Mannings's equation Column 20 Design "Q" to "Q" Full Ratio = Column 10 / Column 18 Column 21 Ratio of Flow Depth (d) to Pipe Diameter (D) in feet (Use Hydraulic Elements Chart, Table 2.2) Column 22 Maximum Design Ratio of Flow Depth (d) to Pipe Diameter (D) in feet (For pipes 8" to 15", d/d = 0.5 or 1/2 full; For pipes greater than 15", d/d = 0.75 or 3/4 full) Column 23 Design "V" Full to "V" Full Ratio (Use Hydraulic Elements Chart, Table 2.2) Column 24 Design Velocity (Column 19 x Column 23)

14 FIGURE 2.2 Date: COMPUTATIONS FOR SANITARY Sheet: 1 of 1 SEWER DESIGN SATURATED GROWTH Date Computed By: ABC Checked By: ABC Assumed Percentage of Saturation = 100% ENGINEER Engineer Location Invert Elevs. Mahole Drain. Area Designation Sewer Line Designation From To Increment Population Cumulative Population Residential Peak Factor Increment Commercial Acres Increment Industrial Acres Increment Peak Inflow GPD Design Q MH# MH# cfs LF ft ft ft/ft Inch cfs fps Ratio d/d d/d Ratio fps SB-1-3 N/A PVC SB-4 N/A PVC SB-5 N/A PVC SB-6 N/A PVC SB-7 N/A PVC SB-8 N/A PVC SB-9 N/A 1 PS PVC Notes: Column 1 Drainage Area Designation Column 2 Sewer Line Designation (Will be Used for Final Design) Column 3 Manhole Designation Column 4 Projected (20-year) Population from Each Individual Drainage Area. Column 5 Total Population Obtained from All Drainage Areas Contributing to that Point. Column 6 Residential Peak Factor. Peak factor = (18+(P) 1/2 )/(4+(P) 1/2 ) Column 7 Amount of Commercial Area Contained Within the Drainage Area in Acres. Column 8 Amount of Industrial Area Contained Within the Drainage Area in Acres. Column 9 Peak Flow Contributed by the Individual Drainage Area. ((Pop x Res Peak Factor x 100 gpcd) + (Comm. area x 1000 gpd/ac) + (Ind. Area x 3250 gpd/ac)) x Percentage of Saturation Column 10 Design Flow Capacity = Total Accumulated Peak Sewage Flow at that Point in Cubic Feet per Second Column 11 Length of Pipe Measured from Center of Manhole to Center of Manhole Column 12 Upstream Manhole Invert Elevation. Column 13 Downstream Manhole Invert Elevation. Column 14 Design Slope = (Upstream Invert - Downstream Invert - Drops Across Intermediate Manholes) / Length Column 15 Pipe Size Column 16 Pipe Material Column 17 Manning's n value (0.011 for PVC and for DI) Column 18 "Q" Full calculated using Manning's equation Column 19 "V" Full calculated using Mannings's equation Column 20 Design "Q" to "Q" Full Ratio = Column 10 / Column 18 Column 21 Ratio of Flow Depth (d) to Pipe Diameter (D) in feet (Use Hydraulic Elements Chart, Table 2.2) Column 22 Maximum Design Ratio of Flow Depth (d) to Pipe Diameter (D) in feet (For pipes 8" to 15", d/d = 0.5 or 1/2 full; For pipes greater than 15", d/d = 0.75 or 3/4 full) Column 23 Design "V" Full to "V" Full Ratio (Use Hydraulic Elements Chart, Table 2.2) Column 24 Design Velocity (Column 19 x Column 23) Length Upper End Lower End Slope Size Pipe Material Manning's n "Q" Full "V" Full Design "Q" "Q" Full Flow Depth Ratio Maximum Flow Depth Ratio Design "V" "V" Full Design "V"

15 SECTION 3.0 DESIGN CRITERIA FOR MANHOLES 3.1 General Manholes shall be installed at the upper end of each line, at all changes in grade, size, or alignment, at all sewer intersections and at the appropriate distances. Maximum distances between manholes shall be as shown in Table 3.1 below. TABLE 3.1 LINE LENGTH BETWEEN MANHOLES Pipe Size Maximum Length of Line Between Manholes 8 to to *Over *Greater spacing may be permitted in larger sewers or in areas where site-specific criteria requires greater lengths with the approval of City Engineering. Every effort shall be made to avoid drop inlets. However, when required, a drop inlet shall be installed in manholes that have an incoming pipe invert elevation 2 feet or more above the outgoing pipe invert and as shown in the standard detail for drop inlets included in the appendix. The drop inlet piping that is encased in concrete shall be ductile iron pipe as shown on the standard detail. Channel inverts inside the manhole shall be built up to prevent splashing as shown in the standard detail for drop inlets. The top of manholes are typically set one foot above grade in non-traffic areas to aid in locating and maintenance purposes. However, in certain instances it is desirable to have the manholes flush with the existing ground. Some examples are as follows: for aesthetic reasons, located inside highway right-of-way, located in pastures, etc. 3.2 Manhole Materials and Construction All standard manholes shall be 4 feet (minimum) diameter pre-cast concrete and shall meet the requirements of ASTM C-478. Larger diameter manholes will be allowed for larger pipes or as required to accommodate sharp changes in alignment or multiple pipes. Manhole sizes for pipes larger than 24 inches shall be verified with manhole manufacturer. All pipe-to-manhole connections shall use pre-fabricated flexible connectors such as A-Lok, or approved equal. New manholes shall have pre-formed holes for pipe installation and existing manholes shall be cored to install pipe and connector. All pipe-to-manhole connections and grade adjustment rings shall be sealed and grouted with non-shrink materials as 3-1

16 specified in the City of Huntsville Sanitary Sewer Specifications. All lift holes except those in cone section shall also be grouted with the non-shrink grout. Lift holes shall not penetrate the wall of the manhole. Manholes shall include a manhole lift system as specified in the City of Huntsville Sanitary Sewer Specifications. All manholes shall be backfilled and tested according to City of Huntsville Sanitary Sewer Specifications and Details. 3.3 Flow Channel 3.4 Bench The flow channel shall conform in shape and size to that of the connecting sewers. Minimum drops shall be increased when curved flow channels are required inside manholes. Refer to paragraph 3.7 for additional information. When pipe diameters are less than 48 inches, a bench shall be provided on each side of the flow channel. The bench slope shall be 1 inch per foot. No pipe shall discharge onto the bench surface. 3.5 Manhole Types Shallow Manhole: A shallow manhole is defined as any manhole that is 5 feet or less in depth, as measured from the invert of the manhole base at its center to the finished ground. Every effort shall be made to avoid using shallow manholes. Standard Manhole: A standard manhole is defined as any manhole that is greater than 5 feet in depth, as measured from the invert of the manhole base at its center to the finished ground. 3.6 Manhole Frames, Covers, and Vents Shallow and standard manholes shall be equipped with traffic-type frames and covers as shown in Appendix B. Sanitary sewer manholes proposed within the 100-year flood boundary shall be designed with the rim elevation a minimum of 1 above the 100-year flood elevation. Manhole rims shall be installed no higher than 3 above the ground surface to allow easy access to the manhole. In an area where the 100-year flood elevation will cause the manhole rim to exceed 3 above the ground surface, the manhole rim shall be installed flush with the ground surface and shall be equipped with a watertight frame and cover and a manhole vent shall be installed. In cases where multiple manholes are required to be equipped with vents, a manhole vent shall be installed at every other manhole. All watertight manhole covers shall be bolted to the frame. See Appendix B for watertight frame and cover and vent details. 3-2

17 Manholes requiring a vent and located within an easement or other areas where raised manholes are not allowed will be required to be constructed with a flat top, as shown on Standard Detail SD-23 in Appendix B. Flat-top manholes will not be allowed for manholes located within traffic areas. Manholes proposed adjacent to drainage ditches, or drainage structures in which there is a potential problem of storm water entering the sanitary sewer, shall be equipped with watertight frames and covers. All manhole frame and covers shall include butyl sealant (ram neck) under the flange of the manhole frame prior to grouting as shown in Appendix B. 3.7 Hydraulic Grade Lines The hydraulic grade line or energy grade line of flow through a manhole shall always be designed to stay within the crown of the pipe. When the pipe size does not change, or increases by only one pipe size, a minimum elevation drop of 0.1 foot shall be applied to the invert of the outgoing pipe. When the pipe will change directions by 90 degrees inside the manhole, a minimum elevation drop of 0.2 foot shall be applied to the invert of the outgoing pipe. Calculations shall be performed to insure that the hydraulic grade line stays within the crown of the pipe when there is reason for concern. These calculation checks may be performed by hand calculations or with the aid of computer software. 3.8 Location of Manholes Manholes located in easements shall be placed outside areas subject to flooding or runoff when possible. Manholes located in streets shall be placed a minimum of 5 feet from the edge of the curb or pavement. Every effort shall be made to place the entire manhole frame and cover within the pavement limits. Manholes shall be positioned outside the normal tire path of vehicles. 3.9 Connecting to Existing Sewers When connecting a new sewer line to an existing manhole, the existing manhole shall be core drilled and flexible connectors, such as A-Lok or approved equal, installed to connect the pipe. When connecting new manholes to existing sewers, the new manholes shall be equipped with flexible connectors, such as Kor-N-Seal or approved equal. The new sewer line or manhole shall be connected to the existing sewer line as shown in the standard details included in the appendix. 3-3

18 3.10 Abandoned Manholes and Sewer Lines All piping connected to abandoned manholes shall be plugged and filled with 24 of grout fill or flowable fill at each end as shown on the standard details. The manhole top shall be removed down to not less than 3 feet below final grade and the remaining portion shall be filled with crushed rock and capped with 12 of concrete or filled with flowable fill as shown on the standard details Testing Requirements The City of Huntsville Engineering Department requires testing of all new public and private sanitary sewer lines and manholes. Minimum testing requirements are included in the City of Huntsville Sanitary Sewer Construction Specifications (see Appendix C). The Contractor shall receive approval of all as-built drawings and the City of Huntsville shall issue all manhole numbers to the Contractor prior to conducting any television inspection activities. The City of Huntsville shall review and approve all television inspection logs prior to the commencement of testing procedures. The Contractor must provide a 72-hour notice prior to testing. A representative from the Engineering Department and/or Water Pollution Control must be present during final testing procedures. An independent testing firm as approved by the Engineering and Water Pollution Control Departments shall conduct testing. A list of approved testing firms is available from Water Pollution Control. All testing costs shall be included in the costs of manholes and pipes. A copy of all as-built drawings, television inspection files, and testing results shall be submitted to Water Pollution Control Lateral Connections All lateral connections made at a manhole shall be made with the invert of the lateral connection equal to the crown of the exiting (downstream) sewer main line. 3-4

19 SECTION 4.0 DESIGN CRITERIA FOR SEWER LINES 4.1 Sizing of Pipe Design calculations for sizing pipe shall be conducted using the following criteria: For pipe sizes 8 to 15, design for ½ full depth flow*. For pipe sizes greater than 15, design for ¾ full depth flow*. * References: 1. Master Sewer Plan, City of Huntsville, April 1997 (currently under revision). 2. Gravity Sanitary Sewer Design and Construction, ASCE Manuals and Reports on Engineering Practice No. 60, WPCF Manual of Practice No. FD-5. The appropriate pipe size and slope to transport the design flow shall be calculated using Manning s Equation as shown below. The minimum pipe size for sanitary sewer in the City of Huntsville is 8 inch. The minimum design velocity is 2 feet/second. A roughness coefficient of n = for ductile iron (n = for PVC) shall be used for sanitary sewers. Manning s Equation V (fps) = (1.486/n)R 2/3 S 1/2 Where n = Roughness Coefficient R = Hydraulic Radius, ft = Area/Wetted Perimeter S = Slope, ft/ft Manning s Equation for Pipes Flowing Full V (fps) = (0.590/n)D 2/3 S 1/2 or Q (cfs) = (0.463/n)D 8/3 S 1/2 Where n = Roughness Coefficient D = Pipe Diameter, ft S = Slope, ft/ft 4-1

20 4.2 Geotechnical Studies A geotechnical study shall be conducted in project areas suspected of rock bedding. Rock soundings shall be at intervals not to exceed 350 to 500 (should match manhole location intervals) feet along the centerline of the proposed sewer and to at least one foot below the depth of the sewer at the location of the sounding. If rock is encountered, then the soundings shall be conducted at closer intervals determined by the Design Engineer and/or City Engineering. 4.3 Surveying of Sanitary Sewer Lines A professional land surveyor licensed in the State of Alabama shall conduct the survey of the proposed sanitary sewer line. The surveyor shall stake out the proposed sewer line as follows: stake each manhole s proposed centerline location with offset referencing, reference each P.I. in the field, and note all benchmarks in the field and on the Plans. The surveyor shall provide drawings meeting all requirements of City of Huntsville. Refer to paragraph 4.8, of this Section for additional information. 4.4 Minimum Cover All sanitary sewers shall have a minimum cover of 3 feet (36 ). Special cases will require approval from City Engineering. Trench bedding and backfill requirements shall be per City of Huntsville Standard Details and Specifications (see Appendix C). 4.5 Pipe Materials and Ratings Listed in Table 4.1 are several general ways to determine which pipe material is best suited for a particular project. Reinforced concrete pipe, ductile iron pipe, and polyvinyl chloride pipe are the City of Huntsville accepted sanitary sewer pipe materials. Use of all other pipe materials must have prior written approval from City Engineering. All gravity and force main piping specified below shall be bedded per City of Huntsville standard details. The same pipe material shall extend from manhole to manhole. No pipe material changes will be allowed between manholes. The minimum design criteria for each pipe material are discussed below. For additional specifications, refer to the City of Huntsville Standard Specifications included in the appendix. 4-2

21 TABLE 4.1 PIPE MATERIAL SELECTION No. Laying Condition Required Pipe Material to Specify* 1 For grades less than 0.60% DIP or PVC *** 2 For grades from 0.60% to 12.00% DIP or PVC 3 For grades from 12.00% to 20.00%. ** DIP with no anchors. 4 For grades from 20.00% to 34.00%. ** DIP with anchors required each 36 feet center to center. 5 For grades from 35.00% and up to DIP with anchors required each %. ** feet center to center. 6 For grades greater than 50.00%. ** DIP with anchors required each 16 feet center to center. 7 For areas where proposed pipe is to be DIP within filled areas. 8 For areas where proposed sewer is at DIP depths greater than 15 feet. Note: Any service risers to DIP from this depth shall also be DIP. 9 For areas within backyard and side lot DIP utility and drainage easement or other difficult to access areas. 10 For crossing ditches and/or streams. DIP (reinforced concrete encasement shall be required if minimum cover is 11 For areas where proposed pipe is at depths less than 5 feet and under traffic conditions less than 3 feet) see standard drawing DIP 12 For crossing existing pipe and roadways. DIP (steel encasement may be required on certain projects.) 13 For boring lines. DIP *All pipe materials shall meet minimum requirements as specified in this manual and in the City of Huntsville Specifications. **The surface area is to be stabilized for grades in excess of 12% (sod, etc.). Steep grades that produce pipe velocities greater than 10.0 fps (Refer to page 4-8) will require prior approval from City Engineering. ***RCP will only be allowed where required pipe size exceeds maximum size available in DIP Reinforced Concrete Pipe (RCP) 4-3

22 RCP shall only be used where the required pipe size exceeds the maximum size allowable in ductile iron pipe. Reinforced Concrete Pipe for gravity flow shall conform to the requirements specified in ASTM C76. Non-air-entraining portland cement with a 28-day compressive strength of not less than 4,000 psi conforming to the requirements of ASTM C150 shall be used. The interior of the RCP shall be lined with a high build, 2-component amine cured epoxy system. The spigot ends shall be coated to give full protection to the area exposed in the bell of the joint. The coatings and/or liners shall meet requirements or specifications of the manufacturer for a sanitary sewer line. All RCP pipe shall meet the following requirements: Standard lengths of at least 8 feet are required, except for end pieces and special pieces. Pipe shall be marked as required by ASTM C76. Rubber gaskets for pipe joints shall be in accordance with ASTM C361 and C443. A 72-hour notice shall be required prior to testing procedures. All final inspections and testing procedures shall be conducted with a representative of City Engineering and Water Pollution Control present. Bedding and backfill requirements shall be as specified in City of Huntsville Sanitary Sewer Specifications. Additional requirements can be found in the City of Huntsville, Standard Specifications. (see section 645-8) Ductile Iron Pipe (DIP) Pipe Size Minimum Pressure Class Up to and including up to and including Greater than Above Ground Pipe Up to and including Above Ground Pipe Greater than

23 The interior of the DIP shall be lined with a cement mortar liner with a bituminous seal coat. This liner shall meet requirements of ANSI C104 and AWWA A21.4. Thickness shall be as specified in the abovementioned standards. An interior liner such as Protecto 401 or approved equal shall be used on ductile iron pipe in areas where Hydrogen Sulfide is a potential problem. All other liners will require approval from City Engineering. The exterior of buried DIP shall receive a 1mil thick coat of either coal tar or asphalt base coating. All other coatings will require approval from City Engineering. A soils test shall be conducted for all project areas suspected of having acidic soils when DIP is specified. Polyethylene tube or sheet encasement shall be used with DIP in project areas where severely aggressive soils are encountered. Polyethylene tube or sheet encasement shall also be used in areas where other metal pipes exist to protect against corrosion caused by stray currents. The polyethylene wrap shall conform to the requirements of ANSI/ASTM D1248. Material and installation methods shall be in accordance with AWWA C105. All DIP shall meet the following requirements: Pipe shall be marked with manufacturer s name or trademark, year produced, and DI or the word ductile. A 72-hour notice shall be required prior to testing procedures. All final inspections and testing procedures shall be conducted with a representative of City Engineering and Water Pollution Control present. Acceptable pipe jointing includes push-in socket joints, such as Tyton, Bell-Tite, and Fastite, mechanical joints, restrained joints and flanged joints (only for above ground), etc. All fittings shall be the same material as the pipe; pressure rated the same as the pipe at a minimum, and shall receive same interior and exterior coatings as the pipe. Bedding and backfill requirements shall be as specified in City of Huntsville Sanitary Sewer Specifications. Additional requirements can be found in the City of Huntsville, Standard Specifications. 4-5

24 4.5.3 Polyvinyl Chloride Pipe (PVC) PVC pipe will only be allowed for pipe diameters of 8 and 10 on mainlines unless written approval is obtained from City Engineering. They shall be minimum SDR 26 (ASTM D-3034). The PVC pipe shall be installed according to standard details and specifications for the appropriate trench type. The standard details are included in the appendix. 4-6

25 All PVC pipe shall meet the following requirements: Standard lengths of at least 12 feet 6 inches are required. Longer sections will be permitted. Pipe shall be marked with manufacturer s name, production lot number, ASTM designation, PVC, SDR rating, and nominal diameter. A 72-hour notice shall be required prior to testing procedures. All final inspections and testing procedures shall be conducted with a representative of City Engineering and Water Pollution Control present. Bedding and backfill requirements shall be as specified in City of Huntsville Sanitary Sewer Specifications. Additional requirements can be found in the City of Huntsville, Standard Specifications. 4.6 Slopes The minimum allowable slopes for each pipe size are displayed in Table 4.2 and the maximum allowable slopes for each pipe size are displayed in Table 4.3. These slopes were calculated using Manning s Equation with a Roughness coefficient of n = (PVC) and n = (DIP, RCP) as shown. The last run or segment of sewer at the upper end of a collector system shall have a minimum slope of foot per foot or greater. This will allow for proper drainage of this dead end line. 4-7

26 TABLE 4.2 MINIMUM ALLOWABLE SLOPES Pipe Slope (ft/ft) Velocity Velocity Diameter (ft/sec) Full (ft/sec) Full (inches) (for n = 0.011) (for n = 0.013) Pipe Diameter (inches) Table 4.3 MAXIMUM ALLOWABLE SLOPES Velocity (ft/sec) Full* Slope (ft/ft) (for n = 0.011) Slope (ft/ft) (for n = 0.013) *Steep grades that produce pipe velocities greater than 10.0 fps will require prior approval from City Engineering. Reference: Design and Construction of Sanitary and 4-8

27 Storm Sewers, WPCF Manual of Practice No. 9, ASCE Manual on Engineering Practice No. 37, 1970 (Fifth Printing 1982), Water Pollution Control Federation The minimum allowable design slope on 8 gravity sewer lines shall be 0.50%. Approval by the City of Huntsville s Engineering Department is required for designs implementing slopes on 8 sanitary sewers less than 0.50% The minimum allowable design slope on 10 gravity sewer lines shall be 0.35%. Approval by the City of Huntsville s Engineering Department is required for designs implementing slopes on 10 sanitary sewers less than 0.35%. 4.7 Easements Installation of sanitary sewer facilities to be maintained by the City of Huntsville shall be constructed within dedicated rights-of-way and utility and drainage easements if available. If no existing easements are available for the proposed sewer, easement plats must be surveyed and prepared by a licensed professional land surveyor and submitted to the City. These documents must include a legal description of the easement(s), legal owner s name, and Deed Book and Page. A licensed State of Alabama professional land surveyor must stamp easement plats. All easement plat submittals (hard copies and digital copies) shall meet the requirements of the Land Acquisition Department. These requirements are available from City Engineering. Special easements such as Railroad Crossings, TVA crossings, and State Highway crossings will require special permitting. The Design Engineer shall be required to submit copies of the plans showing crossings to the appropriate agencies and obtain all necessary permits. Table 4.4 displays the standard minimum permanent easement requirements and recommended temporary easements for different size sewer pipe. Written approval from City Engineering shall be required for additional permanent easement or for decreasing permanent easement widths. The Design Engineer and/or City Engineering shall set the temporary easement widths. The Contractor is required to conduct work in accordance with all safety requirements set by OSHA and all other regulatory agencies. 4-9

28 TABLE 4.4 EASEMENT WIDTHS Minimum Width Recommended Additional Width for Pipe Diameters Permanent Easement* Temporary Construction Easement (TCE)** 8 through ft 20 ft 14 through ft 20 ft 60 and larger 50 ft 0 ft *Additional permanent easement may be required on lines with depths greater than 8 feet. City Engineering and Water Pollution Control shall determine this additional easement. **Additional temporary easements are based on trench side slope of 3:1. Additional temporary easements or trench boxes will need to be used on pipe depths greater than 5 feet. 4.8 Utility Crossings Sanitary sewer lines shall be installed below water mains. A minimum of 10 feet of horizontal clearance between sanitary sewers and water mains shall be maintained. A minimum vertical separation of 18 inches should be maintained between sanitary sewers and water mains. Written approval from City Engineering and Huntsville Utilities is required in cases where these minimum requirements cannot be obtained. A utility crossing detail can be found in the City of Huntsville Standard Details. Other utility crossings shall maintain clearances as specified by Huntsville Utilities and City Engineering. 4.9 Stream Crossings Ductile iron pipe will be required at all creek, stream and ditch crossings. Reinforced concrete encasement shall be required when crossing creeks, streams or ditches if minimum cover of 3 feet cannot be maintained. DIP shall extend from manhole to manhole. Sewer lines shall cross the streams or creeks as near perpendicular to stream flow as possible. The Design Engineer shall be responsible for obtaining all necessary permitting when crossing streams or creeks unless otherwise specified. The Design Engineer shall also be responsible for meeting the design specifications for the permitting. An evaluation of the stream crossing shall be conducted by the Design Engineer to investigate conditions such as the vulnerability of the stream to meander and/or scour. Historical information such as stream scour data is available for review from City Engineering. The stream crossing detail shall then be selected and/ or modified to reflect the minimum requirements established by the permitting agency as well as the limits shown based on the above criteria as well as other applicable conditions. Standard details for these items are included in the appendix. 4-10

29 4.10 Crossing Existing Roadways Sanitary sewers crossing under existing City/County roadways shall be installed by either open trenching or bore and jack with steel encasement pipe as approved by City Engineering. Open trench installation on county roadways will require written permission from the County Engineer. Sanitary sewers crossing existing State roadways shall be installed by bore and jack with steel encasement. The Design Engineer shall prepare all necessary state roadway-crossing permit applications. Ductile iron pipe is required for crossing under all existing roadways. City Engineering shall determine the use of casing pipes on existing roadways. The Design Engineer shall prepare all required roadway-crossing permit applications. Standard details for these items are included in the appendix Testing Requirements City Engineering requires testing of all new public and private sanitary sewer lines and manholes. Minimum testing requirements are included in the City of Huntsville Sanitary Sewer Specifications. All testing costs shall be included in the costs for manholes and pipes. An independent testing firm as approved by City Engineering and Water Pollution Control shall conduct testing, and a list of approved testing firms is available from Water Pollution Control. The Contractor must provide a 72-hour notice to Water Pollution Control prior to testing. A representative from City Engineering and Water Pollution Control must be present during final testing procedures. A copy of all tapes and logs on testing results shall be submitted to Water Pollution Control. 4-11

30 SECTION 5.0 DESIGN CRITERIA FOR SERVICE LATERALS 5.1 General Service lateral connections shall be made with factory-made fittings. Saddle type fittings will not be allowed. The connection between the service lateral and the sewer main shall be watertight. The service lateral shall not protrude into the sewer main. Service laterals shall not cross property lines between adjacent properties. Service laterals shall tie into manholes where practical. The invert of the service lateral shall be placed above the crown of the mainline pipe inside the manhole. All service laterals shall have locator tape installed two feet below ground surface along length of service lateral pipe. Service laterals shall not be allowed to tie directly into main interceptors. All 6 service lines shall tie directly into manholes. Service lateral locations shall be shown on all as-built drawings. The lateral locations shall be shown on different CAD layers/levels than the main lines, per the City of Huntsville s GIS Department. Service lateral connections are not allowed on gravity sewer lines with diameters larger than 10. Service lateral connections shall be made with wye, tee-wye, or other approved fittings only. Standard tee fittings will not be allowed Clarification Statement This Policy Statement serves to clarify and standardize requirements for installation, testing and inspection of 6 and larger building sewers, and manholes which are used as cleanouts on building sewers: City Ordinance adopted the 2003 International Plumbing Code to regulate plumbing work performed on buildings and structures, and governs the installation of building drains and building sewers. The code states that it is intended to provide minimum standards for the design, construction, installation, quality of materials, location, operation, and maintenance or use of plumbing equipment and systems (Sec101.3). It further states that any requirements not specifically covered by this code shall be determined by the code official (Sec 102.9). To ensure that all 6 and larger sewers with manholes are installed and tested to the same standards, the City of Huntsville shall require the following: 5-1

31 5.2 Service Lateral Diameters Building sewers which are 6 and larger, with any manholes, shall be designed, installed, and tested in accordance with the requirements of the City of Huntsville s Design and Acceptance Manual for Sanitary Sewers (Engineering Dept). Specifically, this requires air testing and CCTV of lines and vacuum testing of manholes by a City approved independent contractor, with Water Pollution Control Dept. (WPC) personnel present to observe the test. WPC requires a 72 hour notice to schedule a test observation. Tests should be scheduled by the contractor with WPC s Wastewater Collection Division at Residential service laterals shall not be less than 4 in diameter. 5.3 Pipe Materials and Ratings Service lateral pipes which originate on the mainline shall be the same pipe material as the mainline unless nearby utilities pose problems. However, in the case of service laterals that span roadways, they shall be ductile iron only. Ductile iron pipe service laterals shall be minimum Pressure Class 350. Polyvinyl Chloride service laterals shall be minimum schedule 40. Pipe material shall stay the same from manhole to manhole. 5.4 Installation of Residential Service Laterals Service laterals shall be installed for each lot or property a minimum of 5 feet beyond the right-of-way or easement line. The service laterals shall be installed at the low point of the lot or property when not in conflict with existing utilities. Standard details for service laterals are included in the Appendix. Service laterals shall extend a minimum of 15 beyond the adjacent right-of-way or a minimum of 5 beyond the adjacent easement. 5.5 Installation of Commercial/Industrial Service Laterals A manhole shall be installed at the edge of easement or property line in lieu of a cleanout on all industrial/commercial service lines greater than or equal to 6 inches in diameter. 5.6 Permanent Curb Markers for Service Laterals A permanent marker shall be installed on the curb face at a point which intersects with the service lateral. Curb markers shall be glued or otherwise permanently attached to the curb face at a point which intersects with the service lateral. 5-2

32 Curb markers shall be 2 ½ circular-shaped made of UVHDPE material utilizing a two-color face. The curb marker shall be manufactured by Almetek or approved equal. 5.7 Oil, Water, and Grease Separation A grease trap shall be required to receive the drainage from fixtures and equipment with grease-laden waste located in food preparation areas, such as in restaurants, hotel kitchens, hospitals, school kitchens, bars, factory cafeterias, or restaurants and clubs. A grease trap shall not be required for individual dwelling units or any private living quarters. Such minimal pretreatment requires passage through a grease trap meeting the City's engineering standards and providing a minimum retention time of ten minutes between influent and effluent baffles with 20 percent of the total volume as allowance for a sludge pocket. 5.8 Lateral Connections to Manholes All lateral connections made at a manhole shall be made with the invert of the lateral connection equal to the crown of the exiting (downstream) sewer main line. 5-3

33 SECTION 6.0 PLAN SET REQUIREMENTS 6.1 Standard Requirements for Plan Sets The following standard requirements are guidelines for the preparation of sanitary sewer plans and should not be construed as being the total requirements. City Engineering may at its option require additions to be made in the plans where circumstances warrant. An example plan set is shown at the end of this section. 1. Plans shall be prepared on standard 24 x 36 plan and profile sheets. 2. A cover sheet containing the name of the project, date, city project numbers, mayor, city engineer, city council members, and engineering firm with address and phone numbers, etc. shall be included in all plans. 3. A general sheet containing a location map at an approximate scale of not less than 1 = 1000 feet, a legend, abbreviation listing, general notes, and index of drawings shall be included in all plans. 4. Plan views shall be drawn at a scale of 1 = 50 feet and profiles shall be drawn at a scale of 1 = 50 feet horizontal and 1 = 5 feet or 1 = 10 feet vertical. In areas where existing topographic features are dense, detail sheets at a scale of 1 = 20 feet with the clearance from the proposed main to existing structures clearly defined and noted may be required. The project legend shall be shown on each plan sheet as well as the general sheet when practical. 5. Standard Detail sheets shall include all details required for the project. The details must be the standards accepted by the City of Huntsville as shown in the appendix of this manual. If a required detail is not available in the City of Huntsville standards, the Engineer shall submit a recommended detail for approval by City Engineering. 6. An Alabama licensed professional engineer shall seal and sign all plans. 7. All plans shall contain the following notes: a. The intent of the drawings is that the contractor shall furnish all labor, materials, tools, equipment and transportation necessary for the proper execution of the work in accordance with the Contract Documents and all incidental work necessary to complete the project in an acceptable manner, ready for use, occupancy or operation by the owner. b. Efforts have been made to indicate locations of existing structures, piping, utilities, and topography. However, it is the contractor s responsibility to 6-1

34 field verify exact measurements and locations of all existing items before initiating any construction operations. Any existing structure, piping or utility disturbed or damaged by the contractor during construction operations shall be replaced by the contractor at no additional cost to the owner and/or engineer. Sufficient advance coordination of disruption with the owner of any facility is the total responsibility of the contractor. c. The limits of construction shall be the property lines or easement lines as shown on the plans. The contractor shall acquire any additional easements required for construction at no additional expense to the owner and\or engineer. d. Existing grading and drainage elevations shall be maintained after construction unless otherwise shown on plans. e. All buried pipes shall have a minimum of 3'-0" cover as measured vertically from finished grade to the top of pipe, unless otherwise noted. f. It shall be the contractor's responsibility to work all applicable Drawings and the appropriate specifications as a unit. Any omissions, deletions, or conflicts arising as a result of failure to incorporate all drawings and specifications that apply shall be corrected by the Contractor at no additional cost to the Owner and\or Engineer. g. All sewer construction shall be in accordance with the Standard Specifications for the Construction of New Sanitary Sewers latest edition. h. The contractor shall be totally responsible for TVI, vacuum testing manholes and air testing sewer lines. A 72-hour notice is required prior to testing procedures. Representatives from both the City Engineering office and Water Pollution Control shall be present to verify testing results. i. The Contractor shall provide the City Engineer with a complete set of record drawings (as-builts) in digital Microstation (.dgn) and hardcopy format, and the Contractor/Inspector red-lined drawings upon completion of construction. Drawings shall be referenced to Alabama State Plane Coordinate System, NAD83 Alabama East Zone as described in the "Code of Alabama" (1975), section Surveys shall be tied to a minimum of two accepted GPS monuments or one GPS tie point plus an astronomic observation to determine grid north. A land surveyor licensed in the State of Alabama shall complete the survey. In addition, the record drawings shall show final vertical and horizontal alignment of all buried utilities added or moved as a result of construction. They shall include actual field angles between lines, all service lines and tee locations, all valve vaults and valve boxes, stubouts, and lines, and shall reflect all alignment and grade changes from the design Drawings made during construction. 6-2

35 Record drawings must be completed and submitted prior to acceptance of the sewers into the public system and any connections being made thereto. j. The Engineer shall provide geotechnical information such as borings, soil tests, etc upon written request. k. All concrete, asphalt driveways and other road accesses, shall be sawcut and repaired in as good or better condition as before construction. Property owners shall have access to property at all times during construction. l. Contractor shall supply and install service connections and flex connections in manholes at elevations and deflections as noted on plans for all service laterals shown. m. Service laterals and stubouts shall be extended to property or easement lines as shown on plans. n. Seed, fertilize, and mulch all disturbed areas during construction. o. Fencing may be removed for construction purposes only. Fences shall be reinstalled in their original positions and in as good or better condition as before construction with exception of fence along interstate R.O.W. in which no fence shall be disturbed. p. Contractor shall maintain a 15' minimum excavation clearance at all transmission line tower supports and down guy anchors. q. Contractor shall coordinate in advance and during construction operations with the owner of any fiber optic communication cables in the areas where these utilities may exist. r. Traffic control shall be maintained per the "Manual on Uniform Traffic Control Devices, latest revision. s. The contractor shall be responsible for obtaining and complying with NPDES stormwater permits during entire construction period. A copy of the ADEM permit shall be provided to the City Engineer and maintained on site at all times. 8. All plans shall show the locations of existing and proposed utilities, including but not limited to gas lines, underground telephone, power, and telephone poles, water mains, sanitary sewer lines, storm sewers, etc. 9. All sewer plans shall include a Bench Mark based on U.S.G.S Datum or NAD 1983 Alabama East Zone. Plans that use a manhole invert elevation or an assumed elevation will not be approved. 6-3

36 10. Limits of easements shall be shown on the plans. 11. Show all planimetric features such as driveways, pavement, rights-of-way, property lines, storm drainage, structures, archaeological sites, etc. 12. The direction of North shall be clearly noted on each plan sheet. 13. An Engineering Report shall be submitted with the plans, including criteria justifying the proposed sizing unless City Engineering specifies otherwise. (As required in Section 2) 14. All property lines shall be shown on the plans with Owners and Deed Book and Page noted on plans. 15. A service connection must be provided for each piece of property, parcel or lot. The connection shall be shown as a standard pre-manufactured wye connection and an appropriately sized service line extension (4-inch minimum) to the right-of-way or edge of easement. Handmade Tee s and Y connections are not acceptable. A manhole shall be installed at the end of the service connection for all services equal to or greater than 8-inch. 16. Stationing shall increase upstream with Station being at the downstream end. 17. State Revolving Fund (SRF) projects will require a set of specifications and a half-size set of plans to be submitted to ADEM for review prior to the bid. 18. All City of Huntsville standard details and specifications are included in the appendix of this manual. A checklist for submittal purposes is included in Section 8 as well. 6.2 Design Engineer Specification Requirements Technical specifications prepared by the Design Engineer shall accompany each set of sanitary sewer design plans when required by City Contract. The specifications shall be stamped and signed by a State of Alabama licensed professional engineer. Minimum criteria for the specifications are as follows: 1. Specifications shall be organized according to the sixteen-division format of the Construction Specifications Institute (CSI). 2. Projects to be funded under the SRF program shall have the ADEM front-end specifications incorporated. 3. Specifications at a minimum shall include instructions to the Contractor regarding the following items. 6-4

37 a. Shop drawings and submittals b. Construction schedule c. Quality control d. Materials and equipment (storage, handling, inspection, and protection) e. Project close-out (clean up, final payment, punch list, record drawings) f. Payment procedures 4. Specifications shall be appropriate to the construction of wastewater projects such as gravity sewers and manholes. Inclusion of specifications typical of highway construction or commercial and industrial building or any other construction is generally not appropriate. 5. The specifications shall address, but not be limited to, all information necessary to inform contractors of the design and construction requirements for materials, workmanship, and fabrication of the design project. All technical information that is not addressed on the plans shall be included in the specifications. 6. Specifications shall include definition of rock, rock removal, and how payment and/or bid for rock removal shall be handled. 7. Specifications shall make it clear that it is the Contractor s responsibility to work the Plans and Specifications together as a unit. 8. Specifications shall include only that work which is to be completed under the current contract. 9. Bid forms shall include base bid manufacturer s names for all equipment. 10. Bid forms may include a line item for Aid-to-Construction, to cover potential utility relocation or coordination work, paving or resurfacing, or materials testing when acceptable by City Engineering. 11. Bidder s proposal shall include bid bond and certification regarding debarment, suspension and other responsibility matters. 12. The Contractor s Agreement shall have Payment Bond and Performance Bond appended. 6-5

38 6.3 Projects Utilizing City of Huntsville Standard Specifications City of Huntsville Standard Specifications shall be used for Project Construction when City Contract does not require Technical Specifications. The Design Engineer shall prepare a complete set of Plans per this Manual and the City of Huntsville Standard Specifications as found in the Appendix. The Design Engineer shall also prepare a Bid Quantity sheet and a Cost Estimate for the Project. In the event that the City of Huntsville Standard Specifications do not cover or meet the requirements of the Project Design, the Design Engineer shall prepare Technical Specifications for the additional requirements of the Project. These specifications shall meet requirements of paragraph Submittals Submittals for sanitary sewer design in subdivision development shall be according to this manual, the City of Huntsville Engineering Standards for Construction Improvements (1991), and the most recent Subdivision Regulations Digital Submittals. Regulations are available from City Engineering. All other sanitary sewer design submittals, both public and private, shall be submitted in hard copy and digital form. Digital submittals shall be in either DGN format only. Specifications shall be in Microsoft Word format or compatible. The Contractor shall also be responsible for any other submittals as noted in the specifications and as required by the Design Engineer. 6.5 Record Drawings 1. City Construction Projects: The Contractor shall be responsible for field surveying once construction is complete (to be performed by a registered land surveyor in Alabama). Once surveying is complete, the Contractor is responsible for providing digital record drawings showing all info specified below, as applicable. Final payment, release of retainage, will not be made until digital record drawings have been reviewed for accuracy. All survey field notes, and red-lines should be submitted upon completion. 2. Subdivision Development Projects: The Developer shall be responsible for field surveying once construction is complete (certified by registered land surveyor in Alabama). Once surveying is complete, the Developer is responsible for hiring an Engineering Firm to place the field-surveyed information, as specified below, into a digital format as specified in the digital file requirements listed below. The Developer is responsible for submitting one digital and one hard copy to the City for review and approval, prior to final acceptance of the Subdivision, to include all applicable field notes from 6-6

39 land surveyor. Bonded improvements will need to be incorporated into the record drawings upon completion. 3. Format Requirements for all record drawing submittals: All drawings shall be prepared in Micro Station.DGN format, unless otherwise approved by the City Engineer. Transmittal letters shall consist of a list of files being submitted, a description of the data in each file, and a level/layer schematic of each design file. DGN design files should have working units as follows: master units in feet, no sub-units, and 1,000 positional units. All data submitted should use NAD 1983 Alabama East Zone coordinates as described in The Code of Alabama (1975), section and NGVD Digital files shall be submitted on 4-3/4 CD ROM, 100 MB zip drive, 3 and ½ inch floppy disk, or to the City of Huntsville F.T. P. Site. Engineering Firm/Developer required to certify that record drawings are in the correct format upon submittal. 4. Record Drawing Guidelines, unless otherwise noted by City Engineer: a. Gravity Line i. Horizontal Location of Manholes Northing, and Easting Coordinates ii. Vertical Location of Manholes Lid elevation and Invert elevation. iii. Location of service lateral connection to main line. iv. Changes in length, slope, size, or material of lines. b. Force Mains i. Horizontal Location of Air Relief/Vacuum/Isolation Valves Northing and Easting Coordinates ii. Horizontal and Vertical Location of Fittings/Bends iii. Changes in length, size, depth or material of lines iv. Changes in restraint types c. Pump Stations i. Changes in Structural Requirements (length, width, thickness, cover, laps, bar size, spacing, materials, etc.) ii. Changes in Site Development and/or Landscaping iii. Changes in Equipment 5. Record drawings must be submitted and approved prior to acceptance of the sewers into the public system. 6-7

40 6. Record Drawing Certification: The Design Engineer shall certify record drawings. The following statement shall be added to the cover sheet of the record drawings and signed by the Design Engineer. RECORD DRAWING CERTIFICATION: Based upon the provided survey and construction information, I, the Design Engineer, certify that I have reviewed the information provided to me on this project and determined that this project as constructed will convey the Design Flows as intended during the design phase. No guarantees or warranties are implied on the quality of construction. Signed: Company: Date: 6-8

41 FIGURE 6.1 SAMPLE PLAN SET (Following Page) NOTICE: This sample plan set is shown to display the minimum layout requirements and sheet requirements. It is in no way considered a complete set of plans for a project. All sanitary sewer design projects shall contain a minimum of 4-5 sheets depending on the size and scope of the projects. All finished drawings and plans should contain the appropriate standard details and shall be referenced thoroughly throughout the entire drawing set. It is the responsibility of the Design Engineer to ensure the plans are complete and workable. 6-9

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